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171.
Ju-Kyung Shin So Mi Jeong Yongsug Tak Sung-Hyeon Baeck 《Research on Chemical Intermediates》2010,36(6-7):715-724
MoO3/Pt binary catalysts with various Mo/Pt ratios were prepared by an electrodeposition method for use as the anode in a direct methanol fuel cell. Pt was electrodeposited onto indium tin oxide (ITO) substrate, and then MoO3 was electrodeposited from an Mo-peroxo electrolyte on the top of Pt with different deposition times. The crystallinity of synthesized films was analyzed by X-ray diffraction (XRD), and the oxidation state of both the platinum and molybdenum were determined by X-ray photoelectron spectroscopy (XPS) analyses. Scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM/EDS) was employed to investigate the surface morphology and composition. The catalytic activity and stability for methanol oxidation were measured using cyclic voltammetry and chronoamperometry in a mixture of 0.5 M H2SO4 and 0.5 M CH3OH aqueous solution. Electrocatalytic activity for CO oxidation was also evaluated in a 0.5-M H2SO4 solution. The addition of a proper amount of MoO3 was found to significantly improve both the catalytic activity and stability for methanol oxidation. 相似文献
172.
173.
Uniform snowball zinc sulfide (ZnS) microflowers with nanosheet covering were synthesized using the one step reaction of zinc coordination compounds with thiourea at 160 °C for 24 h. X‐ray single crystal diffraction, electron microscopy, energy‐dispersive X‐ray spectrometry, and X‐ray diffraction were used to characterize the products. The flower‐like ZnS crystals may have some application in catalyst or solar cell devices. This work is also expected to be applied in the fabrication of other transition metal sulfide crystals with special morphology. 相似文献
174.
In order to prevent restenosis after angioplasty or stenting, one of the most popular targets is suppression of the abnormal growth and excess migration of vascular smooth muscle cells (VSMCs) with drugs. However, the drugs also adversely affect vascular endothelial cells (VECs), leading to the induction of late thrombosis. We have investigated the effect of epigallocatechin-3-gallate (EGCG) on the proliferation and migration of VECs and VSMCs. Both cells showed dose-dependent decrease of viability in response to EGCG while they have different IC(50) values of EGCG (VECs, 150 mM and VSMCs, 1050 mM). Incubating both cells with EGCG resulted in significant reduction in cell proliferation irrespective of cell type. The proliferation of VECs were greater affected than that of VSMCs at the same concentrations of EGCG. EGCG exerted differential migration-inhibitory activity in VECs vs. VSMCs. The migration of VECs was not attenuated by 200 mM EGCG, but that of VSMCs was significantly inhibited at the same concentration of EGCG. It is suggested that that EGCG can be effectively used as an efficient drug for vascular diseases or stents due to its selective activity, completely suppressing the proliferation and migration of VSMCs, but not adversely affecting VECs migration in blood vessels. 相似文献
175.
We report a diagnostic method for Anaplasma phagocytophilum (A. phagocytophilum) infection in cattle using a nested PCR and microchip electrophoresis (ME). A. phagocytophilum causes human granulocytic anaplasmosis and granulocytic ehrlichiosis, which are emerging tick‐borne zoonotic diseases. Nested PCR was used to amplify genomic DNA samples extracted from cattle blood. The amplified PCR products were analyzed under a sieving gel matrix of 0.7% poly(ethyleneoxide) (Mr=8 000 000) in a conventional glass microchip. In the ME assay, A. phagocytophilum was analyzed within 35 s with a relative standard deviation of 1.30% (n=5) using a programmed field strength gradient (PFSG) as follows: 615.3 V/cm for 0–24 s, 66.7 V/cm for 24–34 s, 615.3 V/cm for 34–100 s. The ME‐PFSG assay was clinically validated by comparing the 16S rRNA gene levels obtained by this method with those measured using conventional slab gel electrophoresis performed with ten cattle blood samples suspected of A. phagocytophilum infection. In contrast to slab gel electrophoresis, the proposed ME‐PFSG methodology had increased sensitivity (200–450 pg/μL), a faster analysis time (<35 s), and required a smaller sample volume (~162 fL). 相似文献
176.
177.
Huan Xu Jin‐Ling Mi Zhao‐Jian Hu Xiu‐Kai Guo Qun Chen 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(4):o151-o153
An ice‐like hexameric water cluster, stabilized by the flexible bis‐imidazolyl compound 2,3,5,6‐tetrafluoro‐1,4‐bis(imidazol‐1‐ylmethyl)benzene (Fbix), is found in the trigonal R crystal structure of the title compound, C14H10F4N4·2H2O or Fbix·2H2O. The Fbix molecule lies about an inversion centre with one water molecule in the asymmetric unit in a general position. A cyclic chair‐like hexameric water cluster with symmetry is generated with a hydrogen‐bonded O...O distance within the hexamer of 2.786 (3) Å. The Fbix molecule adopts a trans conformation, where the imidazole ring makes a dihedral angle of 70.24 (11)° with the central tetrafluorinated aromatic ring. Each water hexamer is connected by six Fbix molecules through intermolecular O—H...N hydrogen bonds [N...O = 2.868 (3) Å] to yield a three‐dimensional supramolecular network with primitive cubic (pcu) topology. Large voids in each single pcu network lead to fourfold interpenetrated aggregates of Fbix·2H2O. 相似文献
178.
Two new phenolic amides, pharnilatins A (1) and B (2), were isolated from the seeds of Pharbitis nil. These new compounds possess a p-coumaroyl unit with a structurally unique side chain, (2S,3S)-2,3-dihydroxyputrescine. The chemical structures and absolute stereochemistries of the new compounds were determined on the basis of spectroscopic analyses including 1D- and 2D-NMR experiments and chemical reactions. Compounds 1 and 2 exhibited cytotoxicity against A549, SK-OV-3, SK-MEL-2, and HCT-15 human tumor cells. However, none of the compounds inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-activated microglia cells. 相似文献
179.
Anna Fàbregas-Fernández Encarna García-Montoya Pilar Pérez-Lozano Josep M. Suñé-Negre Josep Ramon Ticó Montserrat Miñarro 《Accreditation and quality assurance》2010,15(5):297-304
There is currently no universal or standardized quality system for the recognition of excellence of a research center. Knowledge
and competence may not be enough in the current rapidly changing world in which high productivity and continuous improvement
are essential. The purpose of this study was to assess the impacts of implementing the ISO9001:2000:2000 standard in an academic
research center dedicated to R+D+I (research, development and innovation) in the pharmaceutical industry. The article describes
the stages we followed to implement the ISO9001:2000 system, which was achieved by integrating it into the previous regulatory
system of GMP (Good Manufacturing Practices). As a result of implementing ISO9001:2000, the center has seen distinct improvements,
such as fewer errors in project documentation, improved assessment of customer satisfaction, and the effective implementation
of periodic plans, e.g., in calibration, preventive maintenance, and investments. Overall, ISO9001:2000 implementation has
been beneficial for the organization and could be applied to other research centers. 相似文献
180.
Simonida Lj Tomić Maja M. Mićić Sava N. Dobić Jovanka M. Filipović Edin H. Suljovrujić 《Radiation Physics and Chemistry》2010,79(5):643-649
pH- and temperature-sensitive hydrogels, based on 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA) copolymers, were prepared by γ-irradiation and characterized in order to examine their potential use in biomedical applications. The influence of comonomer ratio in these smart copolymers on their morphology, mechanical and thermal properties, biocompatibility and microbe penetration capability was investigated. The mechanical properties of copolymers were investigated using the dynamic mechanical analysis (DMA), while their thermal properties and morphology were examined by thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The morphology, mechanical and thermal properties of these hydrogels were found to be suitable for most requirements of biomedical applications. The in vitro study of P(HEMA/IA) biocompatibility showed no evidence of cell toxicity nor any considerable hemolytic activity. Furthermore, the microbe penetration test showed that neither Staphylococcus aureus nor Escherichia coli passed through the hydogel dressing; thus the P(HEMA/IA) dressing could be considered a good barrier against microbes. All results indicate that stimuli-responsive P(HEMA/IA) hydrogels have great potential for biomedical applications, especially for skin treatment and wound dressings. 相似文献